pub fn convert_base(num_str: &str, to_base: u32) -> String {
        let parts: Vec<&str> = num_str.split('(').collect();
        let value_str = parts[0];
        let from_base: u32 = parts[1].trim_end_matches(')').parse().unwrap();
    
        // 将原始数值转换为十进制
        let decimal_value = i64::from_str_radix(value_str, from_base).unwrap();
    
        // 将十进制数值转换为目标进制
        let mut result = String::new();
        let digits = "0123456789abcdef";
        let mut n = decimal_value;
        while n > 0 {
            let remainder = n % to_base as i64;
            result.push(digits.chars().nth(remainder as usize).unwrap());
            n /= to_base as i64;
        }
    
        result.chars().rev().collect()
}
